[Octave-bug-tracker] [bug #45631] Line dissapear from plot when modifying "plotboxaspectratio"

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?45631>

                 Summary: Line dissapear from plot when modifying
"plotboxaspectratio"
                 Project: GNU Octave
            Submitted by: None
            Submitted on: sön 26 jul 2015 12.14.00
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.8.1
        Operating System: GNU/Linux

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Details:

This bug is present in booth 3.8.1 and 4.0.0. It also affect both FLTK and
Qt.

When modifying "plotboxaspectratio", it becomes impossible to draw a line.
Only dots works. It only appears for certain input data, suggesting some bad
rounding.

The script:


load mod34_beta2.mat;
tab1=tab;
load mod34_beta.mat;
corrplot(tab(:,4),tab1(:,4),'X','X',1,1);
corrplot(tab(:,7),tab1(:,7),'X','X',1,1);


The helper function exploiting the bug


function corrplot(X,Y,x_label,y_label,X_scale,Y_scale)
        P=polyfit(X,Y,1);
        x=linspace(min(X),max(X),64);
        plot(X/X_scale,Y/Y_scale,'.','markersize',4);
        hold on
        if(strcmp(x_label,y_label))
                set(gca(),'dataaspectratio', [1, 1, 1]);
                set(gca(),'plotboxaspectratio', [1,1,1]); %(1) Works without 
this line
        end
        plot(x/X_scale,polyval(P,x)/Y_scale,'--'); % With (1), this command has 
no
effect, changing '--' to '.', or removing (1) and it works
        drawnow
        xlabel(x_label);
        ylabel(y_label);
        hold off

end


The bug affects `axis equal` since it sets the affected property.



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File Attachments:


-------------------------------------------------------
Date: sön 26 jul 2015 12.14.00  Name: mod34_beta.mat  Size: 4 kB   By: None
Files with data
<http://savannah.gnu.org/bugs/download.php?file_id=34529>
-------------------------------------------------------
Date: sön 26 jul 2015 12.14.00  Name: mod34_beta2.mat  Size: 4 kB   By: None
Files with data
<http://savannah.gnu.org/bugs/download.php?file_id=34530>

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Reply to this item at:

  <http://savannah.gnu.org/bugs/?45631>

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